RCW38CXO - RCW 38 Chandra X-Ray Point Source Catalog
The Chandra observation of RCW 38 took place on 2001 December 10-11 and lasted 96.7 ks. It used Advanced CCD Imaging Spectrometer (ACIS) chips 0, 1, 2, 3, 6 and 7 in very faint mode. The combined field of view (FOV) of the 4 chips in the imaging array (0-3, ACIS-I) is 16.9' x 16.9'. The aimpoint of the array was 8 59 19.20, -47 30 22.0 (J2000.0), and Chandra's roll angle was 51 degrees. The source detection algorithm PWDetect was run on the cleaned events list across the entire ACIS-I array, and found 460 sources, including 31 sources with more than 200 net counts, 49 sources with 100-200 net counts, 71 sources with 50-100 net counts, and 78 sources with 20-50 net counts. NIR matches were found for 349 of the 460 X-ray sources, including 294 of the 360 cluster members and 55 of the 100 nonmembers.
X-ray and IR Point Source Identification and Characteristics in the Embedded, Massive Star-Forming Region RCW 38 Wolk S.J., Spitzbart B.D., Bourke T.L., Alves J. <Astron. J., 132, 1100-1125 (2006)> =2006AJ....132.1100W
A running source number in order of increasing J2000.0 Right Ascension.
An alternative name for the X-ray source using the '[WSB2006]' prefix (for Wolk, Spitzbart and Bourke, 2006) and the source number, as recommended by the CDS Dictionary of Astronomical Nomenclature of Celestial Objects.
The standard Chandra X-ray source designation, using the 'CXO J' prefix and the truncated J2000.0 coordinates of the source (HHMMSS.s-DDMMSS).
The Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.01 seconds of time in the original reference.
The Declination of the X-ray source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 arcseconds in the original reference.
The Galactic Longitude of the X-ray source.
The Galactic Latitude of the X-ray source.
The off-axis angle of the X-ray source, in arcminutes (converted by the HEASARC from the arcseconds in which it was given in the reference paper).
The net counts for the X-ray source in the 0.3 - 8.0 keV energy range, background-subtracted and corrected for the source extraction aperture sixe.
The number of Bayesian block (BB) intervals in which the X-ray source exhibited constant flux at a significance requirement of 95%. Details of the variability analysis are given in Section 4 of the reference paper, but the key point is that a value for this parameter of greater than 1 indicates a variable source.
The number of Bayesian block (BB) intervals in which the X-ray source exhibited constant flux at a significance requirement of 99%. Details of the variability analysis are given in Section 4 of the reference paper, but the key point is that a value for this parameter of greater than 1 indicates a variable source.
The name of the infrared counterpart to the X-ray source, either the 2MASS name or the Very Large Telescope (VLT) name, depending on which data are quoted.
The angular offset between the X-ray and the infrared positions, in arcseconds.
The J-band magnitude of the IR counterpart to the X-ray source.
The uncertainty in the J magnitude of the IR counterpart.
The H-band magnitude of the IR counterpart to the X-ray source.
The uncertainty in the H magnitude of the IR counterpart.
The K_s-band magnitude of the IR counterpart to the X-ray source.
The uncertainty in the K_s magnitude of the IR counterpart.
The V-band extinction A_V of the IR counterpart to the X-ray source. See Section 6 of the reference paper for a description as to how this quantity was caclculated.
The type of emitting surface assumed in the calculation of the V-band extinction A_V: this is either a cool M star photopshere ('M star'), a disk ('Disk'), a higher-mass star photosphere ('GK star'), or a star plus disk combination ('Bright').
The 2MASS flags for the 2MASS sources, or, for VLT sources that were not detected in all 3 bands and hence were subject to large errors due to the lack of color information, the 'FNT' (for faint) notation. If the source is from VLT then there is no color correction.
This parameter flags whether ('Y') or not ('N') the object is a probable cluster member and was created by the HEASARC based on the sources presence in Table 2 or Table 3 of the reference paper, respectively.